Black , 1 1 - Dimensional Graphitic Strips

Graphitic strips (ribbons) can thought of as segments of carbon nanotubes (CNTs), and therefore may posses many of the useful mechanical and electronic properties of CNTs. We have prepared discrete graphitic strips from o-oligophenylenes, using the intramolecular Scholl oxidation. o-Oligophenylenenes were prepared by Ullmann coupling of a tetra methoxy substituted 2,2’-dibromobiphenyl. The methoxy substituents serve to increase solubility and direct the Scholl oxidation. oOligophenylenes were separated by normal phase HPLC and were characterized by H NMR, X-ray crystallography, UV-Vis, and APPI-MS. The key step in the synthesis is the Scholl oxidation of o-oligophenylenes using a combination of hypervalent iodine reagent (PIFA) and BF3·Et2O to yield graphitic strips. Introduction: Graphitic strips (ribbon) and ladder-type polymers have received a great deal of attention for their potential uses in material and polymer chemistry. These all carbon 1dimensional conjugated system are rigid planar sheets, defect free and contain large πsystems, which are similar in structure and function to CNTs. The synthesis and characterization of such material is important due to their semi-conductive properties enabling their use in light emitting diodes, solar cells and field-effect transistors.